How big an earthquake could we have in Ohio?
As a general rule the size (magnitude) of an earthquake is related to the length of rupture of a fault. That is, big faults generate big earthquakes and small faults generate small earthquakes. We can speculate on the potential length of rupture on known active faults in Ohio but inadequate information is available to make such predictions with a high degree of credibility. Most faults in Ohio are poorly known and are not visible at the surface. Seismologists have speculated that active seismic zones in Ohio could theoretically generate an earthquake at least an order of magnitude larger than the largest historic event. Conservatively, they have suggested that the western Ohio seismic zone could generate an earthquake with a magnitude of between 6.5 and 7.0 and the northeastern seismic zone could generate an earthquake with a magnitude of between 6.0 and 6.5.
At this time, there is no evidence that such large earthquakes have occurred in the last 10,000 years in Ohio. However, the historic record of earthquakes in the state is a little more than 200 years, which is short, geologically speaking, and large earthquakes in the eastern United States typically have long recurrence intervals, on the order of centuries or millennia. If Ohio has the potential for an earthquake above 6.0 magnitude, it might occur tomorrow or perhaps thousands of years from now.
[ Earthquake FAQ ] [ Ohio Seismic Network ]
Last update July 20, 2005
Ohio Seismic Network http://www.dnr.state.oh.us/OhioSeis
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